a. Field of the Invention
The instant invention relates to systems that measure position and orientation of medical devices. In particular, the instant invention relates to systems and methods for measuring the position and orientation of a medical device within a non-ionizing localization field.
b. Background Art
It is well known how to generate heart chamber geometry in preparation for cardiac diagnostic or therapeutic procedures. Often, a mapping catheter is introduced into the heart chamber of interest and moved around within the heart chamber, either randomly, pseudo-randomly, or according to one or more preset patterns. The three-dimensional coordinates are measured using a localization system (sometimes also referred to as a “mapping system,” “navigation system,” or “positional feedback system”). The localization system measures the coordinates of the mapping catheter within a localization field, typically by relating a characteristic of the localization field, such as a voltage, experienced by the mapping catheter to a location of the catheter within the field.
A similar process may be used to measure the position of any object, such as an ablation catheter or other medical device, within the localization field. Such devices may be steerable, for example through the use of one or more pull wires that, when placed in tension, deflect the distal end of the device. Often, the deflection plane or planes of such devices are determined through trial and error—that is, the practitioner deflects the catheter and views the deflection on a display connected to the localization system. When the device is rotated, the practitioner may need to repeat this trial and error process. For more advanced steerable devices including multiple pull wires that permit deflection in a greater number of planes, a trial and error approach to identifying deflection planes can be very time consuming and inefficient.